3-106 A 170-kg granite rock (p = 2700 kg/m³) is dropped into a lake. A man dives in and tries to lift the rock. Deter- mine how much force the man needs to apply to lift it from the bottom of the lake. Do you think he can do it?
3-106 A 170-kg granite rock (p = 2700 kg/m³) is dropped into a lake. A man dives in and tries to lift the rock. Deter- mine how much force the man needs to apply to lift it from the bottom of the lake. Do you think he can do it?
Chapter2: Loads On Structures
Section: Chapter Questions
Problem 1P
Related questions
Question
![### Problem 3–106
A 170-kg granite rock (density \( \rho = 2700 \, \text{kg/m}^3 \)) is dropped into a lake. A man dives in and tries to lift the rock. Determine how much force the man needs to apply to lift it from the bottom of the lake. Do you think he can do it?
### Solution Explanation:
1. **Determine the volume of the rock**:
- Use the formula for density: \( \text{density} = \frac{\text{mass}}{\text{volume}} \).
- Rearranging gives: \( \text{volume} = \frac{\text{mass}}{\text{density}} \).
2. **Calculate the buoyant force**:
- Use Archimedes' principle: The buoyant force is equal to the weight of the displaced water.
- Buoyant force = \(\text{volume of rock} \times \text{density of water} \times \text{gravity}\).
3. **Calculate the weight of the rock in air**:
- Weight = \( \text{mass} \times \text{gravity} \).
4. **Determine the net force needed to lift**:
- Net force = \(\text{weight of rock} - \text{buoyant force}\).
This problem can explore concepts of buoyancy, density, and the physical limits of human strength.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F353f4476-2375-44e0-a0df-7fa04e9ee69f%2F4867a7e0-167c-4635-ad43-b3d229a95ca1%2Fbggvbd_processed.jpeg&w=3840&q=75)
Transcribed Image Text:### Problem 3–106
A 170-kg granite rock (density \( \rho = 2700 \, \text{kg/m}^3 \)) is dropped into a lake. A man dives in and tries to lift the rock. Determine how much force the man needs to apply to lift it from the bottom of the lake. Do you think he can do it?
### Solution Explanation:
1. **Determine the volume of the rock**:
- Use the formula for density: \( \text{density} = \frac{\text{mass}}{\text{volume}} \).
- Rearranging gives: \( \text{volume} = \frac{\text{mass}}{\text{density}} \).
2. **Calculate the buoyant force**:
- Use Archimedes' principle: The buoyant force is equal to the weight of the displaced water.
- Buoyant force = \(\text{volume of rock} \times \text{density of water} \times \text{gravity}\).
3. **Calculate the weight of the rock in air**:
- Weight = \( \text{mass} \times \text{gravity} \).
4. **Determine the net force needed to lift**:
- Net force = \(\text{weight of rock} - \text{buoyant force}\).
This problem can explore concepts of buoyancy, density, and the physical limits of human strength.
Expert Solution
![](/static/compass_v2/shared-icons/check-mark.png)
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution!
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
![Blurred answer](/static/compass_v2/solution-images/blurred-answer.jpg)
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, civil-engineering and related others by exploring similar questions and additional content below.Recommended textbooks for you
![Structural Analysis](https://compass-isbn-assets.s3.amazonaws.com/isbn_cover_images/9781337630931/9781337630931_smallCoverImage.jpg)
![Structural Analysis (10th Edition)](https://www.bartleby.com/isbn_cover_images/9780134610672/9780134610672_smallCoverImage.gif)
Structural Analysis (10th Edition)
Civil Engineering
ISBN:
9780134610672
Author:
Russell C. Hibbeler
Publisher:
PEARSON
![Principles of Foundation Engineering (MindTap Cou…](https://www.bartleby.com/isbn_cover_images/9781337705028/9781337705028_smallCoverImage.gif)
Principles of Foundation Engineering (MindTap Cou…
Civil Engineering
ISBN:
9781337705028
Author:
Braja M. Das, Nagaratnam Sivakugan
Publisher:
Cengage Learning
![Structural Analysis](https://compass-isbn-assets.s3.amazonaws.com/isbn_cover_images/9781337630931/9781337630931_smallCoverImage.jpg)
![Structural Analysis (10th Edition)](https://www.bartleby.com/isbn_cover_images/9780134610672/9780134610672_smallCoverImage.gif)
Structural Analysis (10th Edition)
Civil Engineering
ISBN:
9780134610672
Author:
Russell C. Hibbeler
Publisher:
PEARSON
![Principles of Foundation Engineering (MindTap Cou…](https://www.bartleby.com/isbn_cover_images/9781337705028/9781337705028_smallCoverImage.gif)
Principles of Foundation Engineering (MindTap Cou…
Civil Engineering
ISBN:
9781337705028
Author:
Braja M. Das, Nagaratnam Sivakugan
Publisher:
Cengage Learning
![Fundamentals of Structural Analysis](https://www.bartleby.com/isbn_cover_images/9780073398006/9780073398006_smallCoverImage.gif)
Fundamentals of Structural Analysis
Civil Engineering
ISBN:
9780073398006
Author:
Kenneth M. Leet Emeritus, Chia-Ming Uang, Joel Lanning
Publisher:
McGraw-Hill Education
![Sustainable Energy](https://www.bartleby.com/isbn_cover_images/9781337551663/9781337551663_smallCoverImage.gif)
![Traffic and Highway Engineering](https://www.bartleby.com/isbn_cover_images/9781305156241/9781305156241_smallCoverImage.jpg)
Traffic and Highway Engineering
Civil Engineering
ISBN:
9781305156241
Author:
Garber, Nicholas J.
Publisher:
Cengage Learning